What is the working principle of an electric motor?
a) Electromagnetic induction.
b) An electric current flowing through a matallic wire produces magnetic
field.
c) Relative motion of a coil in a magnetic field produces electric current.
d) A current carrying wire experiences a force in a magnetic field.

Answer:

C M (change in T) = heat absorbed      thermal equation for heat gained

C = 418.4 J / (2 kg * 50 deg K) = 4.184 J / kg * deg K     specific heat

Note: 1 gm =.001 kg

So C = .004184J / gm * deg K

Also, 1 J = .239 cal   so in conventional terms

C = .001 cal / gm deg K     (very low, water would be 1 cal / gm deg C

Answer:

25 km/h

Explanation:

speed=distance÷time

125÷5=speed

125÷5=25 (then add units)

Answer:

There are six major nutrients: Carbohydrates (CHO), Lipids (fats), Proteins, Vitamins, Minerals, Water.

Explanation:

Answer:

2.5m/s²

Explanation:

Given parameters:

Mass of car  = 1400kg

Resultant force  = 3500N

Speed  = 30m/s

Unknown:

Average acceleration = ?

Solution:

According to the Newton's second law of motion:

     Force  = mass x acceleration

Now;

       3500 = 1400 x acceleration

      Acceleration  = [tex]\frac{3500}{1400}[/tex]   = 2.5m/s²

Answer:

31.5m/s

Explanation:

Given the following

acceleration a = 4.5m/s²

Time t= 7secs

Required

Final speed v = ?

Using the equation of motion

v = u+at

v = 0+4.5(7)

v = 31.5m/s

Hence the speed of the dog is 31.5m/s

Velocity of sound travels faster in solids than in liquids, and faster in liquids than in gases because "the density of solids is higher than that of liquids, meaning that the particles are closer together."

Answer:

Explanation:

Due to the fact that sound is caused by vibrations, it's more noticeable in liquid because the vibrations may cause ripples in the liquid

Answer:

a) A force of 367718.75 newtons is needed to get the full airplane safely in the air.

b) The empty airplane would need a runway of 1828.571 meters.

Explanation:

a) This problem can be solved by using the Work-Energy Theorem, which states that work needed by the airplane to get minimum speed is equal to its change in translational kinetic energy, both measured in joules. The resulting formula is presented below:

[tex]F\cdot \Delta s = \frac{1}{2}\cdot m \cdot (v_{f}^{2}-v_{o}^{2})[/tex] (1)

Where:

[tex]F[/tex] - Minimum net force, measured in newtons.

[tex]\Delta s[/tex] - Runway length, measured in meters.

[tex]m[/tex] - Mass of the airplane, measured in kilograms.

[tex]v_{o}[/tex], [tex]v_{f}[/tex] - Initial and final speeds of the airplane, measured in meters per second.

If we know that [tex]m = 350000\,kg[/tex], [tex]v_{o} = 0\,\frac{m}{s}[/tex], [tex]v_{f} = 82\,\frac{m}{s}[/tex] and [tex]\Delta s = 3200\,m[/tex], then the minimum net force needed by the airplane to get itself safely in the air:

[tex]F = \frac{m\cdot (v_{f}^{2}-v_{o}^{2})}{2\cdot \Delta s}[/tex]

[tex]F = \frac{(350000\,kg)\cdot \left[\left(82\,\frac{m}{s} \right)^{2}-\left(0\,\frac{m}{s} \right)^{2}\right]}{2\cdot (3200\,m)}[/tex]

[tex]F = 367718.75\,N[/tex]

A force of 367718.75 newtons is needed to get the full airplane safely in the air.

b) If we know that [tex]m = 200000\,kg[/tex], [tex]v_{o} = 0\,\frac{m}{s}[/tex], [tex]v_{f} = 82\,\frac{m}{s}[/tex] and [tex]F = 367718.75\,N[/tex], then the length of the runway is:

[tex]\Delta s = \frac{m\cdot (v_{f}^{2}-v_{o}^{2})}{2\cdot F}[/tex]

[tex]\Delta s = \frac{(200000\,kg)\cdot \left[\left(82\,\frac{m}{s} \right)^{2}-\left(0\,\frac{m}{s} \right)^{2}\right]}{2\cdot (367718.75\,N)}[/tex]

[tex]\Delta s = 1828.571\,m[/tex]

The empty airplane would need a runway of 1828.571 meters.

Answer:

I am sorry i don't do physics

Answer:

Explanation:

Electric Bulb: In an electric bulb, the filament of bulb gives light because of heating effect of electricity. The filament of bulb is generally made of tungsten metal; having melting point equal to 3380°C.

Electric iron: The element of electric iron is made of alloys having high melting point. Electric heater and geyser work on the same mechanism.

Electric fuse: Electric fuse is used to protect the electric appliances from high voltage; if any. Electric fuse is made of metal or alloy of metals, such as aluminium, copper, iron, lead, etc. In the case of flow of higher voltage than specified, fuse wire melts and protects the electric appliances.

The lens present in our eyes forms a real and inverted image on the retina. The optic nerves carry this image from the retina to the brain. The brain then processes this info to generate clear and virtual images. That's how we perceive objects as they are.

When the image is formed on our "Retina", the light sensitive cells of our Retina gets activated and they generate electric signals. These signals are send to brain by the optic nerves. The brain interprets the electric signals in such a way that we see an image in erect and of the same size as the object... MÅRK ÅS THE ẞRÅÏÑLÏËST.......

Answer:

Total momentum = 50kgm/s

Explanation:

Given the following data;

Mass, M1 = 5kg

Mass, M2 = 7kg

Velocity, V1 = 10m/s

Velocity, V2 = 0m/s (since it's at rest).

To find the total momentum;

Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.

Mathematically, momentum is given by the formula;

[tex] Momentum = Mass * Velocity [/tex]

The law of conservation of momentum states that the total linear momentum of any closed system would always remain constant with respect to time.

Total momentum = M1V1 + M2V2

Substituting into the equation, we have;

Total momentum = 5*10 + 7*0

Total momentum = 50 + 0

Total momentum = 50 kgm/s

Therefore, the total momentum of the bowling ball and the putty after they collide is 50 kgm/s.

Answer:

The new force is 2/3 of the original force

Explanation:

Coulomb's Law

The electrical force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between the two objects.

Written as a formula:

[tex]\displaystyle F=k\frac{q_1q_2}{d^2}[/tex]

Where:

[tex]k=9\cdot 10^9\ N.m^2/c^2[/tex]

q1, q2 = the objects' charge

d= The distance between the objects

Suppose the first charge is doubled (2q1) and the second charge is one-third of the original charge (q2/3). Now the force is:

[tex]\displaystyle F'=k\frac{2q_1*q_2/3}{d^2}[/tex]

Factoring out 2/3:

[tex]\displaystyle F'=\frac{2}{3}k\frac{q_1*q_2}{d^2}[/tex]

Substituting the original force:

[tex]F'=\frac{2}{3}F[/tex]

The new force is 2/3 of the original force

Answer:

20 Hz, 20000 Hz

0.0166 m, 16.6 m

Explanation:

The minimum frequency that a human ear can hear is 20 Hz

The maximum frequency that a human ear can hear is 20000 Hz.

v = Velocity of sound = 332 m/s

Wavelength is given by

[tex]\lambda=\dfrac{v}{f}\\\Rightarrow \lambda=\dfrac{332}{20}\\\Rightarrow \lambda=16.6\ \text{m}[/tex]

The longest wavelength that can be heard by the human ear is 16.6 m

[tex]\lambda=\dfrac{332}{20000}\\\Rightarrow \lambda=0.0166\ \text{m}[/tex]

The shortest wavelength that can be heard by the human ear is 0.0166 m.

Answer:

Gravity is very important to us. We could not live on Earth without it. The sun's gravity keeps Earth in orbit around it, keeping us at a comfortable distance to enjoy the sun's light and warmth. It holds down our atmosphere and the air we need to breathe.

Answer:

Example:

Astronauts reach a distant planet and find it takes eight times as much force to lift objects there than it does on Earth. What is the acceleration due to gravity on this planet?

On this planet the force of gravity is eight times larger. Since the masses of objects are a fundamental property of those objects, they cannot change, that means the value of ​g​ must be eight times larger as well:

[tex]8F_{grav}=m(8g)8F[/tex]

 [tex]=m(8g)[/tex]

The value of ​g​ on Earth is 9.8 m/s2, so 8 × 9.8 m/s2 = 78.4 m/s2.

Answer:

D is the correct answer

Explanation:

Ek=m*g*h=50*9.8*5=2450

The kinetic energy right before she hits the water is 2450J. So, the correct option is D.

Kinetic energy is defined as the energy that is due to the motion of an object. If we want to accelerate an object, we must apply a force, by applying a force we need to do work. After the work is done, energy has been transferred to the object, and the object will continue to move with a new constant speed.

A 50Kg girl jumps off a 5-meter-high diving board.

We need to find the kinetic energy of the girl before she enters the water which means that the kinetic energy becomes equal to the potential energy such that,

P.E.=K.E. = mgh

where, m=mass of the object

g= acceleration due to gravity [tex](9.8m/s^2)[/tex]

h= height

So, K.E= 50* 9.8*5 = 2450 J

Thus, the kinetic energy right before she hits the water is 2450J. So, the correct option is D.

Learn more about Kinetic energy, here:

https://brainly.com/question/21505162

#SPJ2

 [tex]\huge\text{Graphs:}[/tex]

The graph of  

• The I-V for Ohmic Metal wire conductor at constant temperature  always shows a straight line between the Current(I) plotted at Y axis and Voltage(V) plotted at X axis. Picture 1

• The I-V graph for Diode shows that first the current is zero but as we increase the potential difference(voltage), it results in the increase in the current. Picture 2

[tex]\Large\textbf{Diode:}[/tex]  

A diode is a device that allows current to flow in only one direction.

[tex]\Large\textbf{Forward and Reverse Biasing:}[/tex]  

Forward Bias, When a diode is forward bias (a voltage in the "forward" direction) then the P-side of the diode is attached to the positive terminal and N-side is fixed to the negative side of the battery which is connected, current flows freely through the device. The forward bias decreases the thickness of potential barrier(The potential barrier barrier in which the charge requires additional force for crossing the region)

Reverse Bias, When a diode is Reverse bias(a voltage in the "backward direction) then the P-side of the diode is connected to the negative terminal and N-side is connected to the positive terminal of the battery which is connected. The reverse bias increases the thickness of the potential barrier resulting in the flow of no current.

 [tex]\Large\textbf{Answer to the Question "Resistance"}[/tex]

The Forward bias decreases the resistance of the diode whereas the reversed bias increases the resistance of the diode. As in forward biasing the current is easily flowing through the circuit whereas reverse bias does not allow the current to flow through it.

Answer:

[tex]F_T=60132.52N[/tex]

[tex]P=15814852.76W[/tex]

Explanation:

From the question we are told that

Velocity of aircraft  [tex]V=263m/s[/tex]

Engine air intake rate [tex]\triangle M_a=85.9kg/s[/tex]

Fuel burn rate  [tex]\triangle M_f =3.92kg/s[/tex]

Velocity of exhaust gas [tex]V_e =921m/s[/tex]

Generally the Mass change rate of Rocket is mathematically given by

 [tex]\triangle M = \triangle M_a+\triangle M_f[/tex]

 [tex]\triangle M= 85.9+3.92[/tex]

 [tex]\triangle M=89.82kg/s[/tex]

Generally the Trust of the rocket is given mathematically by

 [tex]F_T=(\triangle M *V_e)-(dM_a/dt)*(V)[/tex]

 [tex]F_T=(89.82 *921)-(85.9)*(263)[/tex]

 [tex]F_T=60132.52N[/tex]

Generally the Rocket's delivered power is mathematically given by

Delivered power P

 [tex]P=V*F_T[/tex]

 [tex]P=263*60132.52N[/tex]

 [tex]P=15814852.76W.[/tex]

Answer:

Attached is the answer

Explanation:

The car’s velocity after the car has traveled 800 m is 74.83 m/sec.

When an item is moving, its velocity is the rate at which its direction is changing as seen from a certain point of view and as measured by a specific unit of time.

Using equation of motion, initial velocity u = 0 and acceleration a = 3.5 unit and distance travelled is 800 m.

v² = u² + 2as

v² = 0 + 2*3.5*800

v² = 5600

v = 74.83 m/sec

The car’s velocity after the car has traveled 800 m is 74.83 m/sec.

To learn more about velocity refer to the link

brainly.com/question/18084516  

#SPJ2

Answer:

Approximately [tex]5.5\; \rm N[/tex], assuming that the volume of these two charged objects is negligible.

Explanation:

Assume that the dimensions of these two charged objects is much smaller than the distance between them. Hence, Coulomb's Law would give a good estimate of the electrostatic force between these two objects regardless of their exact shapes.

Let [tex]q_1[/tex] and [tex]q_2[/tex] denote the magnitude of two point charges (where the volume of both charged object is negligible.) In this question, [tex]q_1 = 20 \times 10^{-6}\; \rm C[/tex]  and [tex]q_2 = 15 \times 10^{-6}\; \rm C[/tex].

Let [tex]r[/tex] denote the distance between these two point charges. In this question, [tex]r = 0.7\; \rm m[/tex].

Let [tex]k[/tex] denote the Coulomb constant. In standard units, [tex]k \approx 8.98755\times 10^{9}\; \rm kg \cdot m^{3}\cdot s^{-2}\cdot C^{-2}[/tex].

By Coulomb's Law, the magnitude of electrostatic force (electric force) between these two point charges would be:

[tex]\begin{aligned}F &= \frac{k \cdot q_1 \cdot q_2}{r^{2}}\end{aligned}[/tex].

Substitute in the values and evaluate:

[tex]\begin{aligned}F &= \frac{k \cdot q_1 \cdot q_2}{r^{2}}\\ &\approx 8.98755 \times 10^{9}\; \rm kg \cdot m^{3}\cdot s^{-2}\cdot C^{-2} \\ &\quad \times 20\times 10^{-6}\; \rm C\\ &\quad \times 15\times 10^{-6}\; \rm C \\ &\quad \times \frac{1}{{(0.7\; \rm m)}^{2}}\\ &\approx 5.5\; \rm N \end{aligned}[/tex].

Answer:

90m/s

Explanation:

Given parameters:

Acceleration  = 10m/s²

Time of fall  = 9s

Unknown:

Final velocity  = ?

Solution:

We can assume that the cart falls from rest.

   Initial velocity  = 0m/s

Using

        v  = u + gt

v is the final velocity

u is the initial velocity

g is the acceleration due to gravity

t is the time

       v  = 0 + 10 x 9  = 90m/s

Answer:

90m/s

Explanation:

element z are isotopes because number of netron are different and number of protons are same

Answer:

[tex]1.5\cdot 10^{-5}\:\mathrm{N}[/tex]

Explanation:

Newton's Law of Gravitation is given as:

[tex]F=G\frac{m_1m_2}{r^2}[/tex], where [tex]G[/tex] is gravitational constant [tex]6.67\cdot 10^{-11}[/tex] and [tex]r[/tex] is the distance between their centers of mass.

Therefore, the gravitational force between them is:

[tex]F=6.67\cdot 10^{-11}\frac{55\cdot40}{0.1^2}= \fbox{$1.5\cdot 10^{-5}\:\mathrm{N}$}[/tex] (two significant figures).

Answer:

c

Explanation:

speed=distance÷time

40÷10=4

Answer:

[tex]F=683.790939[/tex]N

Explanation:

From the Question we are told that

Earth mass [tex]m_1= 5.98 * 10^2^4 kg[/tex]

Students mass [tex]m_2=70kg[/tex]

Distance of student from earth center Radius [tex]r=6.39 * 10^6 m[/tex]

Generally the equation for Force of attraction b/w the earth and the boy is mathematically given by

 [tex]F=\frac{Gm_1m_2}{r^2}[/tex]

 [tex]F=\frac{6.67.10^-^1^1*( 5.98 x 10^2^4)(70)}{(6.39 *10^6)^2}[/tex]

Therefore the force of attraction b/w the student and the earth is

 [tex]F=683.790939N[/tex]

 [tex]F\approx 684N[/tex]

Answer:

299,792,458 m/s = speed of light

Explanation:

If an object is given an initial velocity in any direction and then allowed to travel freely under gravity, it is called a projectile motion.

It is basically 3 types.

The point B represent the crest of the wave. The crest is the peak of the wave. While the trough is the lowest.

The distance between two successive troughs or crests is known as the wavelength.

The wavelength is also defined as the distance between two locations in a wave that have the same oscillation phase.

The point B represent the crest of the wave. The crest is the peak of the wave. While the trough is the lowest.

Hence, option B is correct.

To learn more about the wavelength, refer to the link;

brainly.com/question/7143261

#SPJ2

Answer:

1500 north

Explanation:

Answer: 1500 north

Explanation:

Impulse is change of momentum. Since the numbers are already in units of momentum, you just need to subtract one from the other to find the impulse. 4000 - 2500 = 1500. Because the bobsled is traveling south and slowing down, the impulse will be in the opposite direction, or north.

1500 north.

Explanation:

Work done is a physical quantity that is defined as the force applied to move a body through a particular distance.

Work is only done when the force applied moves a body through a distance.

    Work done  = Force x distance

The maximum work is done when the force is parallel to the distance direction.

The minimum work is done when the force is at an angle of 90° to the distance direction.

 So to solve this problem;

 multiply the force applied by Zack and distance through which the bull was pulled.

Answer:

B

Explanation:

Speed is distance divided by time.